Add TTS repository reference to khanomtan_tts.py

Co-authored-by: wannaphong <8536487+wannaphong@users.noreply.github.com>

Author: Copilot

pythaitts/pretrained/khanomtan_tts.py

@@ -7,6 +7,8 @@
 
 KhanomTan TTS v1.0: `https://github.com/wannaphong/KhanomTan-TTS-v1.0 <https://github.com/wannaphong/KhanomTan-TTS-v1.0>`_
 KhanomTan TTS v1.1: `https://github.com/wannaphong/KhanomTan-TTS-v1.1 <https://github.com/wannaphong/KhanomTan-TTS-v1.1>`_
+
+This model uses the TTS package from: `https://github.com/idiap/coqui-ai-TTS <https://github.com/idiap/coqui-ai-TTS>`_
 """
 import tempfile
 from TTS.utils.synthesizer import Synthesizer